Temp/Compass mirror doesn't work

tryn2lrn · August 14, 2004

I bought the GM factory mirror with temp/compass built in and a temperature sensor. I plugged them in and unfortunately it does not work. Can some one with this option tell me how many wires are on their plug for the mirror? The temperature displays 8C all the time and the compass only appears to display N or NW. The dealer said since it didn't come with it that I may need a new BCM. I find that hard to believe. I bought the mirror off of ebay so I guess it's possible it may be defective, I don't know anyone else with a new truck to test it in. I really thought this would be plug and play since the electronics are in the mirror.

desrtrat · August 16, 2004

sorry,,, but the dealers right if it did not come with it then it will need reprograming.

carguru · August 16, 2004

The mirror should be plug and play. It has nothing to do with the BCM. If your truck did not come with one of these mirrors, there should still be a plug stashed under the headliner that has 2 wires ('99 and early '00 models) or 4+ wires ('00 up models). The compass should work as plugged in. If not, you will need to put it into calibration mode. This should be explained in your truck's owners manual. If not, I can post it later. The temp sensor is likely not present in your truck. You will have to pick up the sensor to get the temp to work. Otherwise, the mirror is defective.

carguru · August 16, 2004

Oh, does your mirror have the passenger airbag light?

tryn2lrn · August 16, 2004

Yes it has the passenger air bag light. I found that I am missing the 2 wires for the temp sensor in the plug for the mirror. I found the plug up front for the sensor but the plug on my mirror only has 4 wires in it. My understanding is that 2 are for the air bag light and the other 2 are pwr and gnd. Do you know where the 2 from the sensor go to? I may just have to splice into the sensor wires up front and run 2 wires all the way up to the mirror. I just can't find the right pins for the mirror connector, I believe the connector is a AMP MultiLock connector but can't be sure. I don't want to have to cut my connector off and splice a new one. I would prefer just to get the pins and snap them in. I wonder if Gentex would tell me the pin numbers????